This is a long (871 pages of text), often repetitive, occasionally confusing, and very important book. It continues the challenge to the conventional view of the Enlightenment made by Israel five years ago in his The Radical Enlightenment.

The conventional view, as Israel describes it, sees the Enlightenment as an essentially 18th century current, starting with the physics of Newton, passing through Locke and Hume, and finding its most vocal expression in the writings of Voltaire, Montesquieu, Gibbon and the Scots Adam Ferguson, Smith John Millar and Lord Kames. This was, for instance, the view that very much influenced me when I wrote my A People’s History of the World.

Israel sees things very differently. He sees the driving force being a much more radical current that starts in the Netherlands in 1660s with the atheistic philosophy of Spinoza (in which ‘god’ becomes just a way of referring to the material universe) continues there with the writings of the exiled French Huguenot Bayle, wins the allegiance of small, often persecuted, circles of thinkers across Europe (including Vico in Italy) and then forms the decisive influence on Diderot when he produces the Enlightenment’s most significant embodiment, the Encyclopédie, in the 1750s.

The ‘moderate’ current of Newton and Locke through to Voltaire, he shows, was at pains to try to reconcile the advance of scientific knowledge with religious ideology and the established social structure. Newton and Locke accepted Christianity in its entirety, even if there were sometimes qualms about the validity of some miracles, while Voltaire insisted there had to be a ‘supreme being’.

In Newton’s case his apocalyptic religious beliefs were not, as usually presented, just a weird aberration from an essentially mechanical, materialist view of the universe. The intervention of god, he insisted, was necessary to explain why the planets circle round the Sun instead of moving away in a straight line as his physics dictated. Israel suggests that the criticisms of Newton’s views by Leibniz as well as Spinoza’s followers were not as crazy as how they are often presented. Although often based on scientific and mathematical mistakes, they in some ways foreshadowed the insights of relativity theory in the 20th century.

The softness towards existing religious dogma was not just a ploy to conceal their ideas from censors by the moderate current. Its adherents waged continual philosophical warfare against what they called ‘Spinozism’ to such an extent that their efforts to reconcile religion and science won the support of key elements of the Calvinist, Lutheran and Catholic establishments from the 1720s to the late 1740s. Voltaire even had the backing of one of the popes for a period. The attempt at conciliation with religious orthodoxy was matched by endorsement of hierarchical notions of society and opposition to any form of radical democratism or republicanism. The ideal was the post-1688 English set up, where a hereditary monarchy shared power with representatives of a landed elite, so protecting property and the market from both despotism above and the masses below. Defence of property was identified with the rights of the individual – but in such a way as to endorse privilege, including hereditary privilege and in Locke’s case slavery (in which he had a direct financial interest). Not surprisingly, there was acceptance, at least in part, of the developing racist ideology by some of this current (Voltaire and Hume, for example).

It is these trends within the moderate current that have provided postmodernist and postcolonial writers to depict the whole Enlightenment as permeated through and through with ‘Eurocentrism’, ‘Orientalism’ and racism.

But, as Israel shows decisively, the approach of the radical ‘Spinozists’ led in a very different direction. Their starting point was a fundamental break with the old intellectual orthodoxies. They criticised strongly both the tradition of Renaissance ‘humanism’ that provided distorted readings of ancient Greek philosophy to justify the teachings of the Churches and the conciliatory approach of the Newton-Locke tradition. Their materialism led them to assert the fundamental unity of humanity, seeing the lower classes as having the same potential for intellectual development as their rulers, even if ‘education’ was needed to bring this out, and rejecting the notion that some peoples were intrinsically inferior to others. And they drew republican, democratic conclusions, even if they often felt these could not be put fully into effect until the mass of people had been educated away from the superstitious and obscurantist influences. So while Voltaire and Hume accepted some racist notion, Diderot rejected racism and not only opposed slavery and colonialism, but supported the rights of the slaves of the colonial oppressed to fight for their own liberation.

Not surprisingly, the proponents of the radical Enlightenment received a very different response from established society to the moderates. They faced recurrent bouts of repression, and were forced to either to disguise some of their ideas in print or to publish abroad under pseudonyms if they were not to face imprisonment or exile.

Events, however, forced the two currents together in the 1750s (just as the first volumes of the Encyclopédie were being published). By this time, both currents were centred in France. But French Catholicism was divided down the middle. As well as the relatively sophisticated Jesuit wing, prepared to accept some modern scientific notions in order to win people to the faith, there was the mystical Jansenist wing which relied on ecstatic ‘miracles’ for its mass following and therefore opposed both wings of the Enlightenment. It was able in 1750 to create what we would today call a ‘moral panic’ about the impact of supposedly Spinozist texts, forcing the Jesuits and the Royal Court to turn against not just the radical Enlightenment but the Voltairians as well. The Encyclopédie was briefly banned and Diderot got a short spell in prison, and even Voltaire no longer felt safe. It was in this period that he turned his magnificent polemical skills against the counter-Enlightenment, with his slogan ‘Ecrasez l’infame’ (wipe out the infamy, i.e. organised superstitious religion) and, in 1758, the publication of his brilliant and subversive satirical novel Candide. In the process the fundamental differences between the two wings of the Enlightenment could easily disappear from view, opening the way for them to be overlooked ever since and for the Radical current to be virtually written out of intellectual history.

It is this which allows pro-war, Eurocentric and Islamophobic liberals to claim to embody the Enlightenment tradition today, identifying it with the Locke-Voltaire wing (although Locke did not extend his notions of toleration to atheists and he backed slavery). It is this also which enables postmodernist and postcolonial thinkers to present the Enlightenment as a whole as a negative intellectual trend.

In fact, even the moderate Enlightenment was not uniformly Eurocentric, ‘Orientalist’ or racist. Locke endorsed slavery, but tried to justify it on non-racist grounds, while Hume accepted racist ideas but regarded slavery as ‘barbarous’. In a fascinating chapter Israel provides an account of arguments between the Radical Enlightenment on the one side and Christian ideologists and the Moderate Enlightenment on the other. They all agreed that China was an exemplary society, if anything superior to any to be found in Europe, surviving as it had for over 2,000 years. The Radicals claimed this as proof that atheism could form the basis of the most moral of societies. The Christian thinkers and the Moderates argued that Confucianism rested on a belief in god, which proved the necessity of religion for morality. Both sides might have been ignorant of the realities of Chinese society, but it was by no means an ‘Orientalist’ ignorance.

Even more fascinating is the account of the Radicals’ attitude towards Islam. They were far from seeing it as do the B52 liberals who claim to be the heirs of the Enlightenment today. As Israel says, in ‘radical texts’ the ‘image of Islam’ was of ‘a pure monotheism of high moral calibre which was also a revolutionary force for positive change and one which proved from the outset to be both more rational and less bound to the miraculous than Christianity or Judaism’. The Radicals’ ‘sharp criticism of post-medieval Islam’ was ‘for lapsing from its early intellectual openness and love of philosophy and science, as well as its former commitment to tolerance’. Israel also notes that Voltaire was favourable to Islam, as exemplifying his notion of a pure ‘natural religion’ based on a supreme being without superstition and miracles. ‘Voltaire ... gave currency to the ... conception of Mohammed as a great leader, legislator and rational reformer rather than a religious visionary and wonder-worker.’

Bayle, for the Radicals, emphasised the central role of Islamic thinkers from the 8th to the 12th centuries in transmitting and developing the rationalist materialist notions to be found in Greek philosophers. The Andalusian Islamic thinker Averroes (Ibn Rushd) in particular is ‘held up as the man who had the courage single-handedly to combat the bigotry, credulity and crassness of his time’.

Israel provides a devastating refutation in these chapters of those who uncritically interpret Edward Said’s book Orientalism as proving a seamless trend of prejudiced ‘Orientalism’ dominating European thought for millennia and encompassing ‘Aeschylus ... Victor Hugo, Dante and Karl Marx.’ Significantly, Said’s book never mentioned (according to its index) Spinoza or Bayle, and only referred to Diderot and Voltaire in passing (in reading Candide, Said does not seem to have noticed that the hero eventually found tranquility ‘cultivating his garden’ in the Islamic Ottoman empire). Eurocentrism, racism and ‘Orientalism’ were far from being an endemic feature of western Enlightenment thought, but a product of the ability of west European states to dominate the world, something which only really began to happen from the second half of the 18th century onwards. So although traces of them can be found (although not uniformly) in the Moderate Enlightenment, they did not become all-dominant until the counterrevolutionary hysteria which swept Europe’s ruling classes in the aftermath of the French Revolution brought the Enlightenment to an end.

What is more, the way in which the Radical Enlightenment could see their intellectual forebears as being in Confucian China or the Islamic empires as well as in Graeco-Roman and Renaissance worlds shows how mistaken it is, as the B52 liberals and the postcolonials alike claim, to see the Enlightenment as an exclusively ‘western’ product. As Israel puts it, ‘There is no reason one should search only in the western philosophical traditions to find the intellectual roots of, or cultural basis for, personal liberty, comprehensive toleration, equality sexual and racial, and a secular morality of equity ...’

I should say that, despite the wonders of this book, Israel is not a Marxist, but rather someone who takes the egalitarian, democratic goals of the Radical Enlightenment seriously in a way that contradicts much of what capitalism today offers. In the introduction to the book he presents a view of political change – especially the French Revolution – which counterpoises the development of ideas to social changes, and stresses the autonomous role played by the history of ideas. This approach has some advantages over a crude mechanical version of Marxism which sees ideas as a mere reflection of processes taking place independently of them (and therefore of human action). For that version implies simply sitting back and waiting for society to change without our intervention and forgetting Marx’s adage that ideas that gain mass support themselves become a ‘material force’. But Israel’s approach fails to ask why this can happen at certain points in history and not others, why radical thought can guide human practice sometimes and yet radical thinkers spend decades or even generations apparently getting nowhere. The point is that human beings become open to new ideas when their old ways of seeing things no longer fit their situation. But they can only turn to such ideas if there are people already propagating them. And these people are themselves transmitting ideas that are a product of previous periods of social turmoil. So the Enlightenment arose out of attempts to come to terms with the political, social and intellectual upheavals of the 17th century. It then in turn fed into the great political upheavals at the end of the 18th century in North America and continental Europe, especially France.

The book is long and not always an easy read, it lacks a glossary to explain the scores of thinkers and events it refers to, and most people will not have the time to tackle the over 800 pages of each of Israel’s two volumes. But what it says is very important, and let us hope that at some point the author produces a potted popular version which can rescue the Enlightenment from its false friends and its detractors alike.